diff --git a/multisite_user_register.info.yml b/multisite_user_register.info.yml
index 5aab0c4..ac9cf9d 100644
--- a/multisite_user_register.info.yml
+++ b/multisite_user_register.info.yml
@@ -2,6 +2,7 @@ name: Multisite User Register
 type: module
 description: Module for registering user in multiple site.
 core: 8.x
+core_version_requirement: ^8 || ^9
 package: Other
 dependencies:
   - rest
diff --git a/src/Form/MultiSiteUserRegisterAdminForm.php b/src/Form/MultiSiteUserRegisterAdminForm.php
index a37a199..d0f40ed 100644
--- a/src/Form/MultiSiteUserRegisterAdminForm.php
+++ b/src/Form/MultiSiteUserRegisterAdminForm.php
@@ -6,9 +6,6 @@ use Drupal\Core\Form\FormBase;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\StringTranslation\TranslatableMarkup;
 
-/**
- *
- */
 class MultiSiteUserRegisterAdminForm extends FormBase {
 
   /**
@@ -36,7 +33,7 @@ class MultiSiteUserRegisterAdminForm extends FormBase {
       'path',
       'user_picture',
     );
-    $field_definitions = \Drupal::entityManager()
+    $field_definitions = \Drupal::service('entity_field.manager')
       ->getFieldDefinitions('user', 'user');
     foreach ($field_definitions as $key => $value) {
       if (strpos($key, 'field_') !== FALSE) {
@@ -85,7 +82,7 @@ class MultiSiteUserRegisterAdminForm extends FormBase {
       ->getEditable('multisite_user_register.field_name_settings')
       ->set('multisite_user_register_config', $values)
       ->save();
-    drupal_set_message(t('Configurations saved successfully!'));
+    $this->messenger()->addStatus(t('Configurations saved successfully!'));
   }
 
 }
diff --git a/src/Form/MultiSiteUserRegisterDeleteForm.php b/src/Form/MultiSiteUserRegisterDeleteForm.php
index ff338c7..e7ba5ad 100644
--- a/src/Form/MultiSiteUserRegisterDeleteForm.php
+++ b/src/Form/MultiSiteUserRegisterDeleteForm.php
@@ -38,14 +38,12 @@ class MultiSiteUserRegisterDeleteForm extends EntityConfirmFormBase {
   public function submitForm(array &$form, FormStateInterface $form_state) {
     $this->entity->delete();
 
-    drupal_set_message(
-      $this->t('content @type: deleted @label.',
-        [
-          '@type' => $this->entity->bundle(),
-          '@label' => $this->entity->label(),
-        ]
-        )
-    );
+    $this->messenger()->addStatus($this->t('content @type: deleted @label.',
+      [
+        '@type' => $this->entity->bundle(),
+        '@label' => $this->entity->label(),
+      ]
+      ));
 
     $form_state->setRedirectUrl($this->getCancelUrl());
   }
diff --git a/src/Form/MultiSiteUserRegisterForm.php b/src/Form/MultiSiteUserRegisterForm.php
index 26b04ab..f9684ce 100644
--- a/src/Form/MultiSiteUserRegisterForm.php
+++ b/src/Form/MultiSiteUserRegisterForm.php
@@ -81,13 +81,13 @@ class MultiSiteUserRegisterForm extends EntityForm {
 
     switch ($status) {
       case SAVED_NEW:
-        drupal_set_message($this->t('Created the %label Multi Site User Register.', [
+        $this->messenger()->addStatus($this->t('Created the %label Multi Site User Register.', [
           '%label' => $multi_site_user_register->label(),
         ]));
         break;
 
       default:
-        drupal_set_message($this->t('Saved the %label Multi Site User Register.', [
+        $this->messenger()->addStatus($this->t('Saved the %label Multi Site User Register.', [
           '%label' => $multi_site_user_register->label(),
         ]));
     }